Goals from Christian Luyindama and Sofiane Feghouli gave Galatasaray a vital advantage after their 2-0 victory over Hatayspor in the first leg of the Turkish Cup quarter-final.
DR Congo's Luyindama opened the scoring for the hosts with his first goal for the Istanbul giants since he arrived from Standard Liege on loan in January.
The 25-year-old headed in Selcuk Inan's cross in the seventh minute to give Galatasaray an early lead.
After the restart, Feghouli was introduced for Sinan Gumus in the 84th minute and the midfielder netted his second goal in as many matches.
The Algeria international who saved the Lions from defeat against Alanyaspor on Saturday doubled their lead against the second-tier outfit with a stoppage-time effort.
The victory gave Galatasaray an edge ahead of their visit to Hatay for the return fixture on February 26.